The advancement of wireless or mobile telecommunications technology in recent years has been dramatic. The array of services offered today by mobile telecommunication network operators continues to expand. While voice related services were the primary services offered by network operators during the early stages of mobile phone use, there has been an ever-increasing number of data (non-voice) services available to subscribers. Common examples of data services include Short Message Service (SMS), Wireless Application Protocol (WAP) service and Multimedia Messaging Service (MMS).
In respect of data messages the number of services available is increasing. One more recent example of the services network operators have introduced is known as large account services. With large account services, a subscriber pays to receive an SMS message containing news on a chosen topic, for example updates on stock quotes, sports results etc. Another example is concatenated messaging, where a group of SMS messages are sent to deliver content to a mobile phone, for example a ringtone. As network architectures had developed from a predominantly voice traffic arena, most of the earlier network architectures for carrying data services were specifically designed for voice communication. However with the arrival of mobile data services, these architectures were forced to attempt to adapt to cater for the processing of data service communications as well. With the introduction of more and more data message services further adaptation is proving difficult.
When implementing a billing system for a mobile telecommunications network, network operators generally offer both pre and post paid subscriber accounts. Typically in post-paid voice systems, each time a subscriber makes a telephone call, the call details are logged. Periodically, for example on a monthly basis, the network operator bills the customer for the total call costs incurred during the course of the billing period. The cost of each call is determined by a rating applied to the call which is typically influenced by a number of factors. These factors may include not only the call duration, but the time of day, day of the week, call destination and the subscriber class of service (e.g. business or personal).
In the case of prepaid voice systems however, a user maintains a surplus account with the network operator and, when a user attempts to make a call, the balance of the user's prepaid account is checked, and the call is only permitted if the user's account is in credit above a minimum level defined by the network operator. If the user has insufficient credit to pay for the call, a recorded message is typically sent to the user informing them that further calls may be blocked until the user “tops up” their credit. As in the case of post-paid, pre paid voice systems conventionally provide for the rating of voice calls so as to provide a differential billing rate depending on the nature of the voice call.
FIG. 1 shows a typical network architecture 100 used for enabling data communication between two users in a mobile network, i.e. an originator or sender 10 and a receiver 25. Although data communications can vary in type (e.g. SMS, MMS and WAP services), the routing of a data communication will, for simplicity of explanation, be described with reference to a SMS type text message. The sender 10 who is a subscriber to a mobile network composes the text message using the keypad on their mobile phone. Once the message has been composed the user enters or selects a destination telephone number and the message is sent from their phone. On transmission of the message from the mobile telephone the message is routed via the mobile network and passes through the mobile switching centre (MSC) 15 to the home Short Message Switching Centre (SMSC) 20 of the originator 10. The SMSC 20 determines the destination of the message and then routes the message to the recipient 25. A billing module 30 interfaces with the switching centre of the mobile network 15 and the billing of such a message is effected at the network level prior to the forwarding of the message to the SMSC. The subscriber may be billed either a fixed price for the data message, or a price which is influenced by certain factors associated with the transmitted data message. Such a billing system is suitable for implementation when the network operator utilises a post-paid billing method, i.e. when the transaction charges for a plurality of data transmissions are accumulated together and the accumulated cost is billed to the post-paid subscriber on a monthly basis.
However, the above billing system implementation is not so suitable for prepaid subscriber data services. Historically, this method of billing data messages is unable to provide for prepaid subscriber roaming or charge for mobile terminated information data services, as no standards existed to allow the MSC 15 to charge for these types of services. However, recently a new standard for mobile networks, CAMEL (Customized Applications for Mobile Network Enhanced Logic) has been introduced which is attempting to address these problems. The CAMEL 3 standard addresses roaming and the CAMEL 4 addresses Mobile terminated charging. However, CAMEL 4 is not yet available, and while CAMEL 3 is available today, its adoption is not widespread, and the roaming solution relies on both the roaming and home network to be using CAMEL 3 and allowing the roaming network to send charges to the home network. Also, the volume of SMS traffic places a very high load on both the MSC and voice prepaid billing systems of the network.
A further disadvantage is that the technology used to provide data transfer as distinct from voice traffic in a mobile network lacks the functionality to enable the billing of data services in real time. This has the major disadvantage in the implementation of prepaid billing systems using hot billing, where prepaid customers with no available credit are at times able to continue to use data services. For example, prepaid users can still send SMS messages even after their account balance has fallen below the minimum threshold for voice calls. There is also the further problem with regards to the lack of standardisation in SMS charging methods between different MSCs. Furthermore as the billing systems interfacing to MSCs are specifically designed for use in a voice network they do not have the capability to provide advanced billing options for data communications. This has resulted in a significant loss of potential revenue for network operators, who are unable to reap the benefits that would be associated with being able to calculate the cost of each data service so as to depend on several variables associated with the message.
In addition, existing billing systems have also been unable to perform refunds, or charge for concatenated messaging, as the billing system is interfacing with the MSC, which has no knowledge of this information (it is the SMSC which has access to this information). Existing billing systems are also only able to charge based on message length, which is unsuitable for more advanced message such as WAP or MMS type messages, which would more suitably be charged based on content.
International patent application PCT/US01/05677 entitled “Prepaid Short Messaging” describes a method and apparatus for handling a prepaid message service in which the tariffing occurs prior to final transmission of the short messages. FIG. 2 shows a block diagram of such a system. This differs from the architecture shown in FIG. 1 in that a billing module or prepaid messaging server 40 is interfaced to the SMSC. The same reference numerals are used for the same components of the architecture. By providing the prepaid messaging server at the SMSC it is possible to bill specifically on the traffic as it passes through the SMSC and also in a data messaging specific manner. On receipt of a data message from the switching system 15, the SMSC 20 sends a query to the prepaid messaging server 40. This query is sent to an account database within the prepaid messaging server to determine if an account corresponding to the sender of the short message has sufficient funds to pay for the transmission of the short message. If this account has sufficient funds, the short message is transmitted. If, on the other hand, the account had insufficient funds the message is not transmitted. This system is advantageous in that it offers data specific rating and also enables the network operator to charge for data transactions during transfer between parties, and thus eliminates situations where a prepaid subscriber can send messages when they have insufficient funds available.
However, this system necessitates the subscriber maintaining two separate prepaid accounts; one account to charge for data charged services that resides within the prepaid messaging server, and another separate account elsewhere on the network dedicated to bill voice calls, with no provision for the transferring of funds between these two accounts. Therefore, such an architecture requires subscribers to ensure that they have sufficient credit in both their accounts in order to be able to avail of all the services offered by the network operator, and thus forces the subscribers to decide in advance how much credit they are going to require for each individual service i.e. voice and data. This system also does not provide the network operator with the option of deducting the cost of the data service directly from the subscriber's prepaid voice account if desired. Furthermore, the system is only suitable for use with prepaid subscribers.
There is therefore a need for a billing system and method of routing charges associated with data communications through a mobile telecommunication network that overcomes problems associated with the prior art.